1. Field of the Invention
The present invention relates to a binding machine especially for binding a bag with a resin binding piece.
2. Description of the Related Art
As a binding machine which binds an opening of a bag made of a resin such as polyethylene and containing an article(s) to be packed, the assignee of the present application has proposed a binding machine, hereinafter simply named as a bag binder, which automatically fastens a resin binding piece that can be easily attached and detached so as to be repeatedly used, to an opening of a bag (Japanese Utility Model Publication No. Hei. 7-15514).
FIG. 1 shows the bag binder 1. Binding pieces 2 which are configured by a resin plate and linked to one another into a belt-like shape are housed in a binding piece magazine 3. The binding pieces are sequentially fed to a binding device 6 by ratchet pawls 5 of a binding-piece feeding mechanism 4. A cutter (not shown) which is interlocked with the forward movement of the binding-piece feeding mechanism 4 cuts the portion where the leading binding piece 2a and the next binding piece 2b are linked to each other, and a twisting arm 7 of the binding device 6 rotates to twist two legs of the leading binding piece 2a.
The tip ends of the legs are restricted in rotation by a fixed forming jig 8, and hence the binding piece 2a twisted by the twisting arm 7 is bent into a funnel-like shape, so that hooking portions of the tip ends are crosswise engaged with each other.
An opening portion of a resin bag is inserted from the above into a guiding groove 9 which is formed between the binding-piece feeding mechanism 4 and the binding device 6, to be puckered. The above-mentioned series of operations cause the binding piece 2 to be first fitted onto the puckered portion of the bag, and then twisted, with the result that the bag B is bound with the binding piece 2 as shown in FIG. 2.
In the bag binder 1, the binding piece 2 is twisted by the twisting arm 7 so as to be fastened to the bag, and hence a space for rotation of the twisting arm 7 and the binding piece 2 must be ensured. As shown in FIG. 2, therefore, the bag B cannot be bound in a tension state, and the binding piece is attached to an upper position which is separated from the contents of the bag. As a result, a room in which the contents can be moved is formed in the bag. When vegetables or fruits are packed, for example, the vegetables or fruits may rub against each other to produce damages such as scratches or deformation on them.